1. Field of the Invention
The present invention relates to a method of and to an automatic machine for assembling and shaping circular brushes.
More particularly, the present invention is included in the specific field of systems and corresponding automatic machines for assembling the components of circular brushes, in order to shape a circular brush semi-finished product, in which each semi-finished product obtained comprises substantially: a circular finished ring nut, which extends axially along its own axis, and has a first circumferential side, a substantially cylindrical central portion, a second circumferential side, and a central axial hole, in which the said two sides form a circumferential channel in the shape of a xe2x80x9cUxe2x80x9d; a ring, which extends axially along its own axis, and is disposed between the said two circumferential sides of the said finished ring nut, with its own axis disposed coaxially relative to the axis of the finished ring nut; and a plurality of bristles, which are distributed circumferentially and project radially towards the exterior, and are disposed in the shape of a xe2x80x9cVxe2x80x9d, with the vertex inside the said xe2x80x9cUxe2x80x9d-shaped channel, and with the ring disposed in the vicinity of the convex angle of the xe2x80x9cVxe2x80x9d itself, which is formed by the said bristles.
2. Background of the Invention
At present, in order to assemble the components of a brush, semi-automatic machines of various types are used, in which, during assembly, external intervention is required by an operator, who must position manually the various components which are designed to shape the semi-finished circular brush, or by semi-automatic and/or automatic machines, in which multiple operations are required.
This known art has a series of disadvantages.
A first disadvantage is that the presence of an operator gives rise to a corresponding expense which increases the production costs of the corresponding circular brush.
A second disadvantage is that the multiple operations require a lengthy operating time, with a consequent low production capacity in terms of time, and the adoption of complex, costly machines.
A third disadvantage is that assembly of the bristles is particularly complicated, involves a plurality of operations, and leads to malfunctioning.
A fourth disadvantage is owing to the fact that the length of some bristles in the semi-finished circular brush obtained can be incorrect.
The object of the present invention is to eliminate the above-described disadvantages.
The invention solves the problem of creating a system for assembling and shaping circular brush semi-finished products along an assembly line which extends along its own axis, in which each semi-finished product comprises: a circular finished ring nut, which extends axially along its own axis, and has a first circumferential side, a substantially cylindrical central portion, a second circumferential side, and a central axial hole, wherein the said two circumferential sides form a circumferential channel in the shape of a xe2x80x9cUxe2x80x9d; a ring, which extends axially along its own axis, and is disposed between the said two sides of the said finished ring nut, with its own axis disposed coaxially relative to the axis of the finished ring nut; and a plurality of bristles, which are distributed circumferentially and project radially towards the exterior, and are disposed in the shape of a xe2x80x9cVxe2x80x9d, with the vertex inside the said xe2x80x9cUxe2x80x9d-shaped channel, and with the ring disposed in the vicinity of the convex angle of the xe2x80x9cVxe2x80x9d itself, which is formed by the said bristles.
According to the invention a bristle insertion station is provided in which a)-there is provided a folded circular ring nut, which extends axially along its own axis, and has a conical front profiled section which diverges towards the rear, a central cylindrical portion, an inclined rear circumferential side which diverges towards the rear, and a central axial hole, fitted onto a ring nut-holder unit with a conical front head, the axis of the said coaxial ring nut being disposed coaxially relative to the axis of the said assembly-shaping line; b)-the said ring is disposed slightly spaced axially in front of the said folded ring nut, the axis of the said ring being disposed coaxially relative to the axis of the said assembly-shaping line, and thus coaxially relative to the axis of the said folded circular ring nut; and c)-a plurality of bristles is inserted in a circumferentially distributed manner, by being made to pass between the inner circumference of the said ring and the outer circumference of the said head, and thus on the outer circumference of the said folded circular ring nut, until a specific length of bristles is obtained, disposed downstream from the said ring.
The invention also comprises a machine for implementing the method, and which comprises an assembly-shaping line which extends axially along its own axis, and includes: a translator-shaft unit, which is mobile axially by command, and can support and translate axially along the said axis of the said assembly-shaping line a ring nut-holder unit, which, going from the front towards the rear, has a conical head, a radial spreader device, and a shaft; a folder-ring nut unit, which is provided with a circular matrix, which extends axially along its own axis, coaxially relative to the axis of the said assembly-shaping line, and can fold an unfinished circular ring nut in order to obtain a conical profiled section which diverges towards the rear in the vicinity of its front head, and an inclined profiled section which also diverges towards the rear of the circumferential side; a ring-holder unit which is designed to hold in position a ring which has its corresponding axis coaxial relative to the axis of the said line; a bristle-cutter unit, which is mobile axially by command, and is designed to cut a plurality of continuous tufts of bristles which are disposed upstream from the said ring, and a bristle-gripper unit, which is mobile axially by command, and is designed to move the said bristles axially relative to the said ring.